One prior approach to the task of determining the shape of an object is to use a magnetic head captive inside a pin that is to be inserted into a receptacle or opening in a circuit board. Once inside the openings, a group of pins serves to outline the shape or pattern being measured. Then, when a Hall effect sensor, which is mounted on the circuit board, moves along the length of the pins it determines the magnets locations and hence the pins locations.
The Hall effect technique, because it involves an expensive device for making measurements for the purpose described and requires quite exact alignment of the parts involved has serious limitations in use. Accordingly, to overcome these limitations it is a principal object of the present invention to simplify the technique of measuring shapes and patterns of objects.